Spectrograph tool

Abstract

An expanding auger axis with a hollow end adapted to receive an unmovable sensor tube in which gamma ray, gamma spectrograph, and/or neutron sensors may be placed, the auger adapted to rotate or circulate a discrete media about the sensors.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

The present invention claims the benefit of U.S. Provisional Application No. 60/870,327, filed Dec. 15, 2006, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to a method and apparatus for logging the discreet media continuous flow as on drilling rigs during drilling of subsurface strata.

BACKGROUND OF THE INVENTION

During drilling of subsurface formations, drilling mud is circulated down the hole to flow up the drill bit cuttings. The cuttings are separated from the mud and then may be directed to an apparatus for further processing and measurements, for example as described by the author in U.S. Pat. No. 6,386,026 “Cuttings sample catcher and method of use.” and additionally disclosed in U.S. patent application Ser. No. 10/711,333 “Drilling Cutting Analyser System and Methods of Applications.” (Published US 2005-0082468).

Currently an open hole logging tool in the well or down-hole logging tool in the well are used for gamma ray logging, and not at the surface.

It is, therefore, desirable to provide an improved spectrograph tool.

SUMMARY OF THE INVENTION

It is an object of the present invention to obviate or mitigate at least one disadvantage of previous spectrograph tools.

The method and apparatus described here may be added to the previously described auger which provides the capability to process the cuttings in circular motion around a hollow part of the auger in which an unmovable gamma ray and gamma spectrograph sensor is placed for continuous measurements.

The hollow and increased diameter parts of the auger axis is one part of the auger that continuously spins the cuttings around the unmovable sensor tube with gamma ray and gamma spectrograph sensors. That is, the auger shaft 1.2 is rotatably operated by drive means, such as an electric motor 1.6 to rotate the auger 1.7/auger shaft 1.2 relative to the auger housing 1.1. However, the hollow part or void 1.4 provides a void or space adapted for receiving an unmovable sensor tube 1.5 with a gamma ray and gamma spectrograph sensor. Similarly a neutron capture sensor can be placed in the hollow part or void 1.4. The advantage of having the discreet media moving around the sensor is an improved signal to noise ratio which improves the useful signal for further measurement of drill cutting properties as apparent gamma, gamma spectrograph and neutron density porosity. As one ordinarily skilled in the art recognizes, a variety of other information can be obtained from the above sensors.

In a first aspect, the present invention provides an apparatus for logging the properties of a discrete media, including a rotatable auger, having a generally central auger shaft, the auger shaft having at least a portion having a central void, the void adapted to receive a sensor, and an auger housing for containing the auger and the discrete media, wherein the auger is adapted to rotate the discrete media about the sensor.

Preferably, the apparatus of further includes drive means for rotatably driving the rotatable auger. Preferably, the sensor is rotationally fixed relative to the auger housing. Preferably, there is relative rotational movement between the sensor and the auger shaft. Preferably, the sensor is fixed and the shaft rotates. Preferably, the shaft rotates in a first direction and the sensor rotates in a second direction, the second direction opposite the first direction. Preferably, the sensor includes a gamma ray sensor. Preferably, the sensor includes a gamma spectrograph sensor. Preferably, the sensor includes a neutron capture sensor. Preferably, the apparatus further includes a lead shield about the auger housing. Preferably, the auger is further adapted to move the discrete media axially along the generally central shaft. Preferably, the discrete media is cuttings from a drilling operation.

In a further aspect, the present invention provides a method of logging a property of a discrete media, including providing at least one sensor for determining the property of the discrete media, and providing relative movement of the discrete media about the sensor.

Preferably, the discrete media is cuttings from a drilling operation. Preferably, the sensor is rotatably fixed. Preferably, the discrete media is tumbled about the sensor. Preferably, the discrete media is rotated about the sensor. Preferably, the sensor includes a gamma ray sensor. Preferably, the sensor includes a gamma spectrograph sensor. Preferably, the sensor includes a neutron capture sensor.

Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the attached figure, wherein:

FIG. 1 is a spectrograph of the present invention incorporated into an analytical Auger assembly of Surface logging While Drilling apparatus disclosed by author in U.S. Pat. No. 6,386,026 “Cuttings Sample Catcher and Method of Use” and additionally disclosed in U.S. patent application Ser. No. 10/711,333 (Published US 2005-0082468) “Drilling Cutting Analyser System and Methods of Applications”, both of which are incorporated herein by reference.

DETAILED DESCRIPTION

Generally, the present invention provides a method and system for providing spectrograph analysis of a discrete media, such as drill cuttings, for analysis, for example for surface logging while drilling (SLWD).

Drill cuttings are discharged (e.g. from a mini-shaker) to an auger 1.7 at the thick end (e.g. past the 1.3 position). The cuttings then are moved by rotating motion along the auger 1.7 and around it. This rotation exposes the cuttings around the sensors (e.g. in the unmovable sensor tube 1.5 in the hollow part or void 1.4) for a longer time thus increasing the signal measured and increasing the signal to noise ratio. The outside part of the auger housing 1.1 may be covered by lead shield or other shielding for preventing or reducing ground radiation and/or background radiation to affect the measured signal.

The hollow and increased diameter part of auger axis is one part of the auger 1.7 that continuously spins the cuttings around the unmovable sensor tube with gamma ray and gamma spectrograph sensors. The increase in diameter is adapted to provide the hollow part or void 1.4 for placing the unmovable sensor tube 1.5 with a gamma ray and gamma spectrograph censor. Similarly a neutron capture sensor can be put in the unmovable sensor tube 1.5 within the void 1.4. The advantage of having the discreet media moving around the sensor or sensors or hollow part provides increased signal to noise ratio, which improves the useful signal for further measurement of drill cuttings properties as apparent gamma, gamma spectrograph and neutron density porosity. As recognized by one skilled in the art, a variety of other information can be obtained from the above sensors. In addition, a variety of other sensors may be placed in the hollow part or void 1.4, for example within the unmovable sensor tube 1.5.

In the preceding description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments of the invention. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the invention.

The above-described embodiments of the invention are intended to be examples only. Alterations, modifications and variations can be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.

Claims

1. An apparatus for logging the properties of a discrete media, comprising:

a. a rotatable auger, having a generally central auger shaft, the auger shaft having at least a portion having a central void, the void adapted to receive a sensor; and

b. an auger housing for containing the auger and the discrete media, wherein the auger is adapted to rotate the discrete media about the sensor.

2. The apparatus of claim 1, further comprising drive means for rotatably driving the rotatable auger.

3. The apparatus of claim 1, wherein the sensor is rotationally fixed relative to the auger housing.

4. The apparatus of claim 1, wherein there is relative rotational movement between the sensor and the auger shaft.

5. The apparatus of claim 4, wherein the sensor is fixed and the shaft rotates.

6. The apparatus of claim 4, wherein the shaft rotates in a first direction and the sensor rotates in a second direction, the second direction opposite the first direction.

7. The apparatus of claim 1, the sensor comprising a gamma ray sensor.

8. The apparatus of claim 1, the sensor comprising a gamma spectrograph sensor.

9. The apparatus of claim 1, the sensor comprising a neutron capture sensor.

10. The apparatus of claim 1, further comprising a lead shield about the auger housing.

11. The apparatus of claim 1, wherein the auger is further adapted to move the discrete media axially along the generally central shaft.

12. The apparatus of claim 1, wherein the discrete media is cuttings from a drilling operation.

13. A method of logging a property of a discrete media, comprising:

a. providing at least one sensor for determining the property of the discrete media; and

b. providing relative movement of the discrete media about the sensor.

14. The method of claim 13, wherein the discrete media is cuttings from a drilling operation.

15. The method of claim 13, wherein the sensor is fixed.

16. The method of claim 13, wherein the discrete media is tumbled about the sensor.

17. The method of claim 13, wherein the discrete media is rotated about the sensor.

18. The method of claim 13, the sensor comprising a gamma ray sensor.

19. The method of claim 13, the sensor comprising a gamma spectrograph sensor.

20. The method of claim 13, the sensor comprising a neutron capture sensor.